Impact of starvation on fat content and microbial load in edible crickets (Acheta domesticus)

Abstract

Interest in insects as food is increasing worldwide, particularly in industrialised countries. Insect-based ingredients are considered novel foods in Europe and there are unresolved concerns regarding food safety. Microbial counts in insects can be high, posing potential health risks to consumers and possibly causing rapid deterioration by spoilage microorganisms. Gut emptying by starvation prior to killing could reduce the microbial load in the insect gut but could also lead to fat loss and lower energy content, reducing the profitability of production. This study evaluated the microbial load (total aerobic counts (TAC), Enterobacteriaceae) in house crickets (Acheta domesticus) starved for 0 h (control), 24 h, and 48 h, and the corresponding fat losses. The 24 h starvation group showed significantly lower (P=0.004) Enterobacteriaceae counts of one log cfu/g, but not TAC, (compared to the control group). TAC was significantly increased (P=0.002), by almost one log cfu/g in the 48 h starvation group compared with the control. Sex of the insects had no significant effect on microbial numbers (P=0.72 and P=0.46 for TAC and Enterobacteriaceae, respectively). Starvation for 24 h decreased fat content in crickets (P=0.02), indicating potential production losses. This shows that starvation is not an effective method for reducing microbial loads in edible crickets.